This invention relates to an apparatus for feeding sheets, more specifically to an apparatus for continuously separating and feeding the uppermost sheet of a plurality of sheets.
An apparatus which stores many thin sheets made of, e.g., paper, metal or plastic, and separately feeds the stored sheets one by one is generally known.
For example, a copying apparatus is provided with an automatic original document feeding apparatus as the sheet feeding apparatus in which original documents to be copied are automatically separated one by one when they are stored collectively in a storage chamber, and are then fed toward a copying table.
As shown in FIGS. 1 and 2, a prior art sheet feeding apparatus has an original document table 4 to carry a stack of original documents 2. Since the original document table 4 is slanted, the original documents 2 are moved toward the region between feeding rollers 6 and a separating roller 8 by the force of gravity. The feeding rollers 6 and the separating roller 8 are rotated clockwise as indicated by arrows in FIG. 1. The feeding rollers 6 are in contact with the upper surface of the uppermost original document 2a, while the separating roller 8 is in contact with the lower surface of another original document or the lower surface of the lowest of two or more other original documents 2b. As shown in FIG. 2, the separating roller 8 lines halfway between the two feeding rollers 6 in a offset manner. The uppermost document 2a in contact with the feeding rollers 6 is delivered in the feeding direction as the feeding rollers 6 rotate, while the other original document 2b, in contact with the separating roller 8, is returned.
Although the forward edges of the documents 2 on the document table 4 are trued up once, they may sometimes become irregular when the documents 2 are inserted between the feeding rollers 6 and the separating roller 8 directly from the original paper table 4. Thus, some documents under the uppermost document 2a may come into contact with the feeding rollers 6 before the uppermost original document 2a does. As a result, the upper-most document 2a may not be fed first, and so, the documents may not be fed in the proper order.